A valve timing adjusting device is known in the art, for example, as disclosed in Japanese Patent Publication No. 2002-295207.
According to the above prior art, the valve timing adjusting device is provided in a rotation transmitting system, in which rotation of an engine is transmitted from a driving shaft to a driven shaft of the engine for opening and closing an intake valve or an exhaust valve of the engine. In the valve timing adjusting device, pressure of working oil in an advancing chamber and a retarding chamber formed in a housing is changed to rotate a vane rotor relative to the housing, so that a valve opening/closing timing is controlled. A relative movement of the vane rotor to the housing is limited when one of vanes (a specific vane) is brought into contact with a partitioning wall of the housing.
According to the valve timing adjusting device, the specific vane may be broken or deformed by an impact force applied to the specific vane, when the specific vane is brought into contact with the partitioning wall. When the specific vane was broken or deformed, the vane rotor is further rotated beyond a predetermined angular range relative to the housing until another vane is brought into contact with another partitioning wall of the housing. As a result, a rotational phase difference between the vane rotor and the housing becomes larger, which may cause an adverse effect, such as, a contact between the valves, a contact between the valve and a piston, abnormal combustion and so on. Then, the engine may be damaged.